sterilizable sheathpe with .[.heat.].

ABSTRACT

A video endoscope is provided which has an inner cylindrical body member containing the optics and electronics in a manner which is impervious to liquid so that the inner member can be soaked in a disinfectant between uses. An outer rigid cylindrical sheath is provided into which the innersterilizable and therefore is in a sterile condition at the time of use. The inner body releasably locks into the outer sheath. The outer sheath also includes an accordion shaped sleeve at the proximate end which can be drawn down around the trailing cables containing the optics and electronics so that the entire endoscope is sterile for use within the operating room. After use, the inner body member can be removed and the outer sheath can be disposed of or it can be resterilized by heat for use at a subsequent time. Any containments from the body of the patient will be removed with the outer sheath and kept completely separated from the inner body member so that there can be no transmittal of containments from the body of one patient to that of a subsequent patient.

TECHNICAL FIELD

This invention relates to a video endoscope and more particularly tosuch an endoscope having a moisture tight inner cylindrical bodycontaining electronics and optics which can be disinfected by soakingand an outer rigid sterilizable sheath for containing and covering theinner body during an operation, the outer sheath being sterilized byheat and having a sterilizable sleeve for extending over the trailingcable containing the electronic and optic fibers.

BACKGROUND ART

Over the years many developments have been made in the endoscope art.Particularly, these developments have been attempts to provideendoscopes which will serve a variety of functions and which aremaintained in a sterile condition during use.

Ersek et al. U.S. Pat. Nos. 3,794,091 and 3,809,072 each disclose aflexible sheath which is sterile at the time of manufacture and can berolled up onto an endoscope to provide sterility. However, there is noseal at the proximate end of the sheath and therefore bacteria can enterbetween the endoscope and sheath and there is no provision formaintaining the distal end of the endoscope in a sterile or protectedcondition.

Russel U.S. Pat. No. 3,866,601 discloses a speculum in which apenetrating tube slidably receives a guide tube and is surrounded by aflexible sheath.

Ibe U.S. Pat. No. 4,132,227 discloses an endoscope surrounded by ahollow cylindrical sheath extending toward but not to the distal end ofthe endoscope in order to create a fluid channel in the space betweenthe sheath and the endoscope.

Smith U.S. Pat. No. 4,201,199 discloses an endoscope surrounded by arigid glass or plastic tube having an enlarged bulb at its distal end tospace tissue away from the viewing window of the endoscope. The windowis formed at an angle to provide viewing of a site offset from the axisof the endoscope.

Yoon U.S. Pat. No. 4,254,762 discloses an endoscope surrounded by asheath having a transparent lens at its distal end. The sheath may be atleast partially open at its distal end for use with endoscopes havingbiopsy channels.

Hampson U.S. Pat. No. 4,327,735 discloses a catheter surrounded by atransparent, collapsible sleeve through which the catheter projects atits distal end.

Silverstein et al. U.S. Pat. No. 4,646,722 discloses another endoscopehaving a sterile flexible sheath which can be rolled up along theendoscope. A channel is provided between the endoscope and sheaththrough which biopsies can be taken. The sheath is not sealed at theupper end and will not maintain the sterility which is required withinan operating room.

D'Amelio U.S. Pat. No. 4,721,097 discloses another flexible sheath foruse on an endoscope which has no seal at the upper end and does notprovide the sterility required in an operating room.

Sidall et al. U.S. Pat. No. 4,741,326 discloses a further flexiblesheath which is rolled up along the endoscope and does not providesterility or protection of the entire endoscopic device.

Brown British Patent No. 1,405,025 discloses a proctoscope surrounded bya concentric tube for providing a fluid channel.

DISCLOSURE OF THE INVENTION

In accordance with the present invention, a rigid video endoscope isprovided which comprises an inner cylindrical body member having adistal end and a proximate end. A light transmitting element is sealedto the distal end of the body member. An image sensor is mounted againstthe light transmitting element within the body member. An electroniccable within the body member has a distal end connected to the imagesensor and a proximate end extending beyond the proximate end of thebody member and connectable to a video control unit. At least one fiberoptic bundle for light transmission is provided within the body memberand has a distal end adjacent the light transmitting element and aproximate end extending beyond the proximate end of the body member andconnectable to a xenon, halogen or incandescent light source. A strainrelief fixture is sealingly attached to the proximate end of the bodymember with the electronic cable and jacketed fiber optic bundleextending therethrough and sealed to the fixture. An outer rigidcylindrical heat sterilizable sheath, having a distal end and aproximate end, is provided for receiving the inner body member and is ofsubstantially the same length as the body member. A window is sealed tothe distal end of the sheath. An accordion-folded, heat sterilizable,cylindrical sleeve is mounted adjacent the proximate end of the sheathand is extendable along the electronic cable and the optical bundle fora substantial distance to maintain sterility of the video endoscopewithin the sterile field of the operating room. Means is provided forreleasably locking the body member within the sheath.

A tab can be provided on the sleeve for extending it along theelectronic cable and fiber optic bundle. A releasable locking means caninclude a bayonet slot at the proximate end of the sheath and a pin atthe proximate end of the body member which is releasably engageable withthe bayonet slot. If desired, the window can be a prism for viewing atan angle to the longitudinal axis of the endoscope.

In one embodiment the body member is concentrically aligned with thesheath. In another embodiment the body member is eccentrically mountedwithin the sheath. In this later arrangement the window has aperturestherein and channels within the sheath corresponding in number to theapertures to provide access to the site under investigation. Thesechannels can be used for providing gas or a steerable device can beinserted through one of them to carry out a procedure, such as taking abiopsy at the site. It also could provide a channel for a laser fiber.The body member may be backed filled with nitrogen under pressure tominimize the possibility of any liquids entering into that device.

With this arrangement, the inner cylindrical body member contains all ofthe optics and electronics and can be disinfected by soaking it in adisinfecting solution. However, disinfecting is not sterilization andtherefore is generally not acceptable for use within the operating room.It particularly is not acceptable in open surgical procedures and inorthopedic surgery and neurosurgery. Thus, the rigid sterilizable sheathon the exterior can be properly sterilized by heat treatment and thenslipped over the inner cylindrical body. The accordion-folded sleeve onthe sheath can be extended along the optical bundle and electronic cablefor a sufficient distance to provide a sterile barrier between them andthe operating site. This outer sheath can be made of disposable materialor it can be resterilized for subsequent usage. Thus, all portions ofthe device which come in contact with the patient can be sterilized eventhough the associated electronics and optics cannot be sterilized. Afteruse, any contaminates from the patient's body will be removed with theouter sheath and not contact the inner body member. Thus, thecontamination cannot to transmitted to the next patient since the bodymember will be inserted in another sterile sheath.

The term "light transmitting element" as used herein is intended toinclude any type of light transmitting device which may have any one orseveral optical qualities. For example, it may simply be a transparentpanel made of glass, plastic or sapphire. On the other hand, it maycomprise one or more lenses for magnification or to increase the fieldof view. It can include a series of adjustable lenses to providevariable magnification and serve as a microscope.

Additional advantages of this invention will become apparent from thedescription follows, taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the inner cylindrical body member whichforms a part of the video endoscope of this invention;

FIG. 2 is a perspective view of the outer cylindrical heat sterilizablesheath which forms the other part of the video endoscope of thisinvention;

FIG. 3 is a condensed, longitudinal section, taken along line 3--3 ofFIG. 1, showing the internal details of the cylindrical body member;

FIG. 4 is an enlarged vertical section, taken along line 4--4 of FIG. 3,showing the arrangement of the image sensor and optical fiber bundles;

FIG. 5 is an enlarged vertical section, taken along line 5--5 of FIG. 3,showing the position of the electronic cable and the fiber optic bundleswithin the body member;

FIG. 6 is a condensed longitudinal section, taken along line 6--6 of theFIG. 2, showing further details of the heat sterilizable sheath;

FIG. 7 is a condensed longitudinal section, showing the cylindrical bodymember positioned within the heat sterilizable sheath;

FIG. 8 is a fragmentary perspective view of an alternative videoendoscope;

FIG. 9 is an enlarged vertical section, taken along line 9--9 of FIG. 8,showing the arrangement of the body member within the sheath and thepositioning of the gas channels;

FIG. 10 is a fragmentary perspective view, similar to FIG. 8, butshowing a passageway for use with a steerable device; and

FIG. 11 is a fragmentary section of an alternative construction whereinthe window of the sheath is in the form of a prism.

BEST MODE FOR CARRYING OUT THE INVENTION

In accordance with this invention a video endoscope is provided whichhas an inner body member B, shown in FIGS. 1 and 3, for containing theoptics sterilizable sheath S for receiving the body member and providinga sterile outer casing for coming in contact with the patient and forextending over the connecting cables to provide a sterile environmentfor the operative procedure on the patient.

The inner body member M has a cylindrical housing 10 provided at itsdistal end with a light transmitting device 12 which is sealablyattached thereto to minimize the possibility of any fluids entering atthis location. An image sensor 14, such as a CCD is mounted on theinside of light transmitting device 12 for receiving light transmittedthrough the window at the investigative site, such as within a bodycavity. The image sensor.Iaddend.device, depending upon application.This CCD may be on the order of 1.0 mm×1.0 mm. A typical laproscope is0.8 cm to 1.2 cm in diameter and would utilize a correspondingly largerCCD device, a typical arthroscope is 4.0 mm in diameter and wouldutilize a much smaller CCD sensor. The window may include optics tofocus an image on the CCD and provide a focal length of 0.5 cm to 15 cm,depending on the intended use of the endoscope. Field of view may bealtered by the use of different lenses and may range from 15° to 140° ormore. An electronic cable 16 has a distal end connected to the imagesensor 14 and runs longitudinally through housing 10, as shown in FIG.3.

Conveniently, optical fiber bundles 18 have distal ends positionedadjacent light transmitting element 12 and spaced around image sensor14. The exact number of optical fiber bundles and type of fiber willdepend upon the particular usage of the endoscope. Four such opticalfiber bundles have been shown in the drawings, one being positioned oneach of the four sides of image sensor 14. However, a greater or smallernumber could be provided, as required. The number of optical fiberbundles may be optimized to allow transmission of various lightfrequencies, including laser light. These optical fiber bundles 18 alsorun through housing 10 and pass through a strain relief fixture 20 whichseals the proximate end of housing 10. This fixture is also sealedaround these cables and extend beyond the fixture through the center ofa connecting cable 22 whose opposite end is connected to a videoprocessing unit 24 having a suitable viewing screen (not shown) andlight sources (not shown) as required and as is apparent to one skilledin the art. The cylindrical housing is completely sealed against theentry of moisture by window 12 and fixture 20. It also may be backfilledwith nitrogen gas under pressure to help keep moisture out. After eachuse, it can be soaked in a disinfectant, such as gluleraldehyde orChlorox.

Conveniently, the distal end of housing 10 is provided with oppositelyextending pins 26 for connection to a bayonet slot on sheath 5 asdescribed below. Also, an 0-ring 28 is provided for forming a seal withouter sheath S, as described below. The seal could also be a threadedseal, with a threaded collar on the outer unit fitting into a threadedcollar in the inner unit.

Sheath S comprises a cylindrical housing 30 which has a window 32 at itsdistal end and a bayonet slot 34 at its proximate end for cooperatingwith pins 26 to lock inner body member B within outer sheath S.Advantageously, an accordion-folded sleeve 36 is provided adjacent theproximate end of housing 30 and has a flange 38 attached to housing 30,as by adhesive and includes a pull tab 40 for extending the sleeve overstrain relief fixture 20 and connecting cable 22 as best seen FIG. 7.These parts can be made of Teflon or other materials which can withstandhigh sterilization temperatures. The window can be made of glass orsapphire or polycarbonate which can stand the sterilization heat orother materials which are clear and withstand high temperatures of heatsterilization.

Referring to FIG. 7, it can be seen that when the endoscope is ready foruse, the inner body member is locked within outer sheath S and lighttransmitting element 14 thereof is adjacent window 32 of the sheath.Thus, the inner body member is completely encased in the sterile outersheath. Furthermore, the sterile sleeve 36 extends over the strainrelief fixture and connecting cable to provide a completely sterileendoscope in the operating room and particularly at the site at whichthe operation or medical procedure is being conducted.

After use, the inner body member can be removed from the outer sheath Sand sleeve 36 by twisting it slightly to release pins 26 from bayonetslot 34 whereupon it can be withdrawn. The outer sheath and sleeve 36can be thrown away or it can be heated to a sufficient temperature andpressure for sterilization.

Also, it will be apparent that any contamination from the body of thepatient which may repose on the outer sheath or the sleeve will bestripped away from the inner body member along with the outer sheath andtherefore not be transmitted to the body member. The inner body membercan then be soaked in a disinfectant and reinserted in another sterileouter sheath and sleeve for use on a subsequent operation. Obviously, asupply of the relatively inexpensive outer sheath and sleeve assembliescan be maintained so that the inner body member can be quickly madeready for a subsequent operation. The video endoscope of this inventioncan be used as a laparoscope, cystoscope, arthroscope, and forpelviscopy. With suitable optics, it could be used as a sterileoperating microscope.

An alternative embodiment is shown in FIGS. 8-11 wherein a larger outersheath S' is provided around inner body member B. This sheath S' has acylindrical housing 30, with a lens 32, at the distal end and a sleeve36, at the proximate end attached by means of a flange 38, Theadditional space is occupied by one or more tubes or channels, such astubes 42 and 44 for supplying gas or fluids to the site underinvestigation. Conveniently, these tubes have control valves 46 and 48respectively for controlling the flow of the gases and to prevent gasleakage during a procedure. The gas can be carbon dioxide which may beprovided for the purpose of clearing and distending the site underinvestigation for better viewing. Also, a vacuum could be appliedthrough one of the channels for aspiration of unwanted material from theviewing site. Conveniently, the distal ends of these tubes are connectedto apertures 50 and 52, respectively in window 32'. These channels ortubes can be used for insertion of laser fibers, biopsy devices,grasping devices, etc.

In FIG. 10 the same device is shown for use with a steerable device. Inthis case, a channel or tube 54 is provided which enters through housingwall 30' and extends longitudinally therealong and through aperture 52.Within this tube 54 is a steerable device, such as a biopsy samplingdevice 56 which is operated by a joy stick 58, as shown.

Finally, a further alternative embodiment is shown in FIG. 11 whereinthe outer sheath S is provided with a prism 60 in place of the frontwindow 32 so that the device can be used to view at any suitable angleto the longitudinal axis of the endoscope. The image sensor may beplaced at various angles to the longitudinal axis of the tubularhousing, for instance at 30°, 45°, or 90°. In this variation, thesterilizable sheath would be placed at a corresponding angle to matchthe orientation of the sensor.

From the foregoing, the advantages of this invention are readilyapparent. An endoscope has been provided which is formed in two parts,an inner body member and an outer sheath. The inner body member containsall of the optics and electronics and is sealed against moisture so thatit can be soaked in a disinfectant between usages. However, in mostsituations such disinfecting is not sufficient for safe subsequent usein the operating room. Therefore, an outer sheath is provided which canbe heat sterilized prior to use and can be slipped over the inner bodymember and releasably locked thereto to provide an outer sterilecovering. The outer sheath includes an accordion shaped sleeve at theproximate end which can be extended over the trailing cables of theinner member which contain the optical fibers and electronic cables toprovide a sterile covering so that the device can be used in theoperating room at the operating site. After use, the inner body membercan be removed from the outer sheath and the sheath can either be thrownaway or resterilized. Also, any contamination from the body of thepatient will be removed with the outer sheath and will not come incontact with the inner body member, thereby minimizing any transmittalof disease from one patient to the next.

This invention has been described in detail with reference to particularembodiments thereof, but it will be understood that various othermodifications can be effected within the spirit and scope of thisinvention.

I claim:
 1. A rigid video endoscope comprising:an inner cylindrical bodymember having a distal end and a proximate end; a light transmittingelement sealed to said distal end of said body member; an image sensormounted against said element within said body member; an electroniccable within said body member, having a distal end connected to saidimage sensor and a proximate end extending beyond said proximate end ofsaid body member and connectable to a video processing unit; at leastone fiber optic bundle within said body member, having a distal endadjacent said element and a proximate end extending beyond saidproximate end of said body member and connectable to the videoprocessing unit; a strain relief fixture sealingly attached to saidproximate end of said body member, said electronic cable and said fiberoptic bundle extending through said fixture, said fixture being sealedthereto; sterilizable sheath, having a distal end and a proximate end,for receiving said inner body member and being of substantially the samelength as said body member; a window sealed to said distal end of saidsleeve; sterilizable, cylindrical sleeve mounted adjacent said proximateend of said sheath and extendable along said electronic cable and saidoptical bundle for a substantial distance for maintaining sterility ofsaid video endoscope within an operating room; and means for releasablylocking said body member within said sheath.
 2. Apparatus, as claimed inclaim 1, further including:a tab on said sleeve for extending it alongsaid electronic cable and said fiber optic bundle.
 3. Apparatus, asclaimed in claim 1, wherein said releasable locking means includes:abayonet slot at said proximate end of said sheath; and a pin at saidproximate end of said body member which is releasably.Iaddend.. 4.Apparatus, as claimed in claim 1, wherein:said window is a prism forviewing at an angle to the longitudinal axis of said endoscope. 5.Apparatus, as claimed in claim 1, wherein:said light transmitting meansincludes optics for magnifying an image.
 6. Apparatus, as claimed inclaim 1, wherein:said light transmitting means includes optics forchanging the field of view.
 7. Apparatus, as claimed in claim 1,wherein:said body member is concentrically aligned within said sheath.8. Apparatus, as claimed in claim 1, wherein:said body member iseccentrically mounted within said sheath.
 9. Apparatus, as claimed inclaim 8, further including:means defining at least one aperture in saidwindow; and at least one channel within said sheath between said sheathand said body member and having a distal end communicating with saidaperture to provide access to a site under investigation.
 10. Apparatus,as claimed in claim 9, wherein:said aperture defining means defines aplurality of apertures; .Iaddend.having a distal end communicatingrespectively with one of said apertures; means supplying a gas throughat least one of said channels; and valve means connected to a proximateportion of said one channel to control the flow of gas.
 11. Apparatus,as claimed in claim 1, wherein:a steerable device is inserted throughone of said other channels for carrying out a procedure at the siteunder investigation.
 12. Apparatus, as claimed in claim 1, wherein:saidbody member is backfilled with nitrogen under pressure. sterilizablesheath for an endoscope having a cylindrical body portion which containswithin it an image sensor, an electronic cable connected to the sensorand at least one optical fiber bundle, said sheath comprising:acylindrical housing, having a distal end and a proximate end, forreceiving the body portion of said endoscope; a light transmittingelement sealed to said distal end of said sleeve for transmitting alight image of the site under investigation to the image sensor;sterilizable, cylindrical sleeve mounted adjacent said proximate end ofsaid sheath and extendable along said electronic cable and said opticalbundle for a substantial distance to maintain sterility of saidendoscope within an operating room; and means for releasably lockingsaid distal ends of said body and said housing together.